Staying warm in the winter is a must, but that does not mean you need to empty your wallet for warmer clothes. Here are a few sweaters that I found for under $20, I've also listed other site I recommend for end-of-season sales. Keep in mind I'm a huge fan of layering, so none of these are thick wool sweaters.
1. Delia's Kara Cardigan - $19.99
I love the cuff detail on this one.
2. Forever21 Casual Cardigan - $15.40
As a note this style runs a little small, so if you're looking for a looser fit, go a size up.
3. Forever21 Mixed Striped Cardigan - $19.80
4. Delia's Emily Pointelle Cardigan (other colors available) - $9.99
This would be for a dressy shirt that needs more sleeve.
5. Victoria's Secret Silk Cashmere V-neck Cardigan Sweater (other colors available) - $19.99
This is an amazing steal! There are so many other colors and $20 for silk and cashmere!
I really recommend keeping an eye on lloy's clearance, Victoria's Secret's clothing sales and Charlotte Russe's in-store clearance.